Africorchestia, a new genus of coastal sand-hoppers (Amphipoda, Talitridae), is described from western Africa and southwestern Europe. Africorchestia includes five species: A. fischeri (H. Milne Edwards, 1830); A. quadrispinosa (K.H. Barnard, 1916); A. skoogi (Stebbing, 1922); A. spinifera (Mateus, 1962); and A. tricornuta (Shoemaker, 1920).

Consider a rectangular art gallery divided into n rectangular rooms, such that any two rooms sharing a wall in common have a door connecting them. How many guards need to be stationed in the gallery so as to protect all of the rooms in our gallery? Notice that if a guard is stationed at a door, he will be able to guard two rooms. Our main aim in this paper is to show that Èn/2 ̆ guards are alway...

We model formation and evolution of transverse dune fields. In the model, only the cross section of the dune is simulated. The only physical variable of relevance is the dune height, from which the dune width and velocity are determined, as well as phenomenological rules for interaction between two dunes of different heights. We find that dune fields with no sand on the ground between dunes are...

Endemic plants inhabiting coastal sand dunes show augmented extinction risks due to the dynamic nature of dunes and strong human pressure on coastal areas. To investigate the survival strategies and threats to long-term survival of such species, we combined genetic, morphological and biogeographical approaches, using the example of Hieracium eriophorum (Asteraceae) and its putative cryptic sist...

This study aims to analyze silica's morphological characteristics and electrical properties based on the river coastal sand. Iron samples were taken from Sompang sand, East Lombok Coastal Sand Gading, Mataram City. The silica was synthesized using sol-gel method with a sintering temperature variation of 100 175 ℃. Morphological analysis done SEM-EDX. iron sand included measuring dielectric cons...

the silversides or sand smelts are found in coastal areas of temperate to tropical seas and in fresh water. there are about 14 genera and 68 species with only one native species in the caspian sea basin, atherina caspia . in this review, the systematics, morphology, distribution, biology, economic importance and conservation of the caspian silverside of iran are described, the species is illust...